(This group doesn’t include some high-ranking and otherwise outspoken US tech leaders: Apple’s Tim Cook, Google’s Sundar Pichai, Facebook’s Mark Zuckerberg, Microsoft’s Satya Nadella and Twitter’s Jack Dorsey have all voiced their thoughts on recent political controversies but did not sign the letter.)

“Great ideas come from all parts of society, and we should champion that broad-based creative potential,” the signers wrote. “Donald Trump, meanwhile, traffics in ethnic and racial stereotypes, repeatedly insults women and is openly hostile to immigration.”

Note that while the tech industry loves to talk about itself as a meritocracy, its own record on ethnic and gender diversity needs improvement — a point thatPresident Barack Obama has made more than once.

The letter also decries Trump’s intention toshut down the parts of the internet used by theISIS. The letter says this proposal demonstrates “both poor judgment and ignorance about how technology works.”

One early participant in the drafting of the open letter, which began a few weeks ago, said the authors’ overriding concern was Trump’s habit of focusing on how things used to be.

“We cannot thrive or lead (or perhaps even survive) by continuing to aim at being the best at what we used to be the best at,” Washington startup hub1776 co-founder Donna Harris wrote in an e-mail. “We need leaders who can acknowledge that.”

What they — and we — don’t know

Towards the end, this short document pivots to admit that critiquing Trump’s tech policy amounts to wrestling with shadows.

“We believe that government plays an important role in the technology economy by investing in infrastructure, education and scientific research,” it states. “Donald Trump articulates few policies beyond erratic and contradictory pronouncements.”

The Consumer Technology Association noted this shortfall ina Thursday statement calling on Trump and Libertarian candidate Gary Johnson to state their intentions. Asked CTA president Gary Shapiro: “Do they have any plans at all on spectrum, investment, broadband, training and education and competitiveness?”

Indeed, it’s strange that the applicant for America’s top job has a “continued absence of a tech/innovation agenda,” as 1776’s Harris mentioned. That doesn’t prove Trump has no thoughts on those issues; but it does mean it’s time for this businessman to share his ideas on this key part of the nation’s business.